Electrostatic book copier

ABSTRACT

A compact or tabletop electrostatic book copier having at the top thereof an exposure station on which a book is laid with a mirror and lens optical system for projecting an image of the book page to a more or less vertical exposing station. Paper is fed from a paper safe at the bottom of the machine through a charging unit substantially horizontally, and then substantially vertically up to the exposing station where the paper is exposed. From the top of the exposing station the paper is fed face down in a downwardly diagonal direction over a developing station, and along an inverting reentrant path to a delivery station immediately above the developing station where the copy is delivered face up.

7 United States Patent inventors Meyer L. Sugnrman Northbrdo'k; William B. .larzembski, Riverside, both of ill.

Appl. No. 718,142

Filed Apr. 2, 1968 Patented Sept. 28, 1971 Assignee Opto/Graphics, lnc.

Kenilworth, lll.

ELECTROSTATIC BOOK COPIER Primary Examiner-John M. Horan Attorney-Olson, Trexler, Wolters & Bushnell ABSTRACT: A compact or tabletop electrostatic book copier having at the top thereof an exposure station on which a book is laid with a mirror and lens optical system for projecting an image of the book page to a more or less vertical exposing sta- 5 Claims, 3 Drawing Figs. I

tion. Paper is fed from a paper safe at the bottom of the 355/10 machine through a charging unit substantially horizontally, lm'cl 8 13/10 and then substantially vertically up to the exposing station 0f SEHICI'I I l where the a er i expo ed From [he top of the exposing ation the paper is fed face down in a downwardly diagonal References cued direction over a developing station, and along an inverting UNITED STATES PATENTS reentrant path to a delivery station immediately above the 3,395,610 8/1968 Evans 355/1 1 developing station where the copy is delivered face up.

2 m r e CONT/PD L ELECTROSTATIC BOOK COPIER Prior electrostatic book copiers have been subject to various deficiencies. In many instances the delivery station has been too far removed from the exposure station at which the book to be copied is placed, or has been inconveniently located, or both. Printing cycles have often been too long, and this has sometimes been due to too long a paper-feeding path, and it has sometimes been due to too much wetting of the paper in the developer or toner, requiring an extensive drying cycle.

In accordance with the present invention, it is an object thereof to provide a compact or tabletop electrostatic book copier wherein the finished copy paper is delivered immediately adjacent the book or other document or paper being copied.

It is a further object of the present invention to provide an electrostatic book copier wherein the paper feed path is of a minimum length, thus leading to a short operating cycle.

It is yet another object of the present invention to provide a book or the like copying machine wherein exposed paper is developed face down in contact with a liquid developer, thereby avoiding any substantial wetting of the paper, and is then fed back along a reentrant path for delivery face up at a delivery station.

It is further an object of this invention to provide a book or the like copying machine wherein copy paper, after wet development, is fed in close proximity to an illuminating lamp to'promote rapid drying of the copy paper by radiant heat from the lamp.

Further objects and advantages of the present invention will beapparent from the following description when taken connection with the accompanying drawings wherein:

FIG. 1 is a top perspective view of an electrostatic book copier constructed in accordance with the present invention as taken from one end thereof;

FIG. 2 is a top perspective view taken from the opposite end; and

FIG. 3 is a longitudinal sectional view.

Referring now in greater particularly to the drawings, a bookcopier l constructed in accordance with the principles of the present invention includes a generally rectangular housing 12 having a top surface providing an exposure station 14 and a copy delivery station 16. The exposure station comprises a rectangular opening having a plate glass sheet 18 on which the material to be copied, such as a book 20, is placed. A semiflexible cover 22 is pivotally connected at 24 to vertically movable pins 26 for allowing the pivot point to move from a position immediately above the top of the copying machine to the extended position shown in FIG. 3 to permit the cover to overlie the rather thick portion of a book. The housing 12 continues diagonally down at 28 to the left of the exposure station for the opposite side of the book to hang down without the necessity of completely flattening the book. A lip 30 extends transversely across the machine between the exposure station 14 and the diagonal housing portion 28, and is received in the crease at which the book is opened to prevent the book from inadvertently sliding down the diagonal or inclined surface 28. (it will be appreciated that whenever a conventionally bound book is opened, the adjacent pages do not lie completely parallel, but present a trough or crease between them at their junction.)

Below the glass plate 18 of the exposure station 14 and symmetrically disposed with respect thereto is a pair of reflectors 3,2 and 34 each comprising a flat reflecting surface 36 and 38, each diagonally disposed, and having at its lower end a more or less U-shaped reflection portion 40 and 42. Light bulbs 44 and 46, preferably quartz iodide bulbs, are disposed within the U-shaped portions 40 and 42, but offset from the center thereof, being relatively spaced away from the flat reflecting surfaces 36 and 38, respectively. In this position that bulbs do a minimum of shadowing of the light reflected from the U- shaped portions of the reflectors 40 and 42, and the result is a very even illumination across the glass 18, and hence uniform illumination of the book or other material to be copied.

Straight below the plate 18, and near the bottom of the housing 12, is an obliquely disposed mirror 48 for reflecting the image of the book page or other exposed material through a lens system 50 up to an exposing station 52 shortly to be described in greater detail. it will be noted at the present time that the exposing station is nearly vertical, but tipped somewhat to the left of the vertical in the position shown in FIG. 3.

Near the bottom right front of the photocopier in the position shown in the drawings there is provided a paper safe 54in the nature of a drawer having on its undersurface a downwardly opening channel 56 received on a guide 58 near one side of the paper safe. Near the opposite side, the paper safe simply rests on an upwardly directed flange 60. The paper safe can be pulled from the front of the machine, riding on the channel and guide 56, 58 and the flange 60.

The paper safe includes a paper-supporting plate 62 pivotally mounted at the left end (FIG. 3) for movement between the lowered broken line position where the support rests on a channel 64 serving as a limit or down stop, and an upper position shown in solid lines. A leaf spring 66 bears against the under side of the plate 62 and urges it up. In the upper limit position an intumed flange 68 on a bracket 70 engages the free edge of the paper support plate 62 to prevent it from rising too far. A stack of paper 72 is supported on the plate 62, and the uppermost sheet thereof is engaged by a rubber roller 74.

The roller 74 turns only for a brief time at spaced intervals, and feeds the top sheet of paper from the stack 72 over the flange 68, which serves as a separator for the successive sheets of paper, into converging flanges 76 forming the entrance to an electrostatic charging station 78 in the nature of a corona discharge device. Upper and lower opposed rollers 80 and 82 receive the leading edge of the paper from the electrostatic charging station or unit 78, and feed the paper up to the exposing station 52. To this end there are also lower and upper rollers 84 and 86 disposed above the exposing station 52. A belt 88 passes over the rollers 82 and 86 and moves therewith, the front reach of the belt being indicated at 90, and the back reach thereof at 92. The back reach passes over a belt-tensioning device including a belt-engaging member 94 and a leaf spring 96. The belt may be made of a synthetic material such as dacron or rayon, and is perforated or otherwise provided with interstices, or alternatively may be a plurality of strips or individual belts. The front reach of the belt 88 passes over the open front of a vacuum pan 98, whereby air tends to pass through the front reach of the belt, and thereby holds a sheet of paper tightly against the belt in the exposing station.

The engagement of the paper from the paper safe with'the front reach of the belt 88 causes the paper to turn a corner of somewhat greater than 90 degrees in feeding from the electrostatic charging unit 78 up to the exposing station. Even though the paper is on the downwardly facing reach of the belt, it stays firmly against the belt due to the vacuum pan or chamber 98 and the perforations in the belt. As the paper rounds the comer and moves past roller 80, it engages the arm of a switch l00 which may be of any suitable type, including optical, but which preferably is of the type having a low travel and requiring only a very low force. The purpose of the switch 100 will be set forth later.

A similar switch 102 is provided above the exposing station 52 and is actuated when paper carried by the belt 88 reaches the top of the exposing station.

The paper carried by the belt 88 is stationary during the making of an exposure, as will be set forth somewhat hereinafter. After the exposure has been made, the belt again moves to carry the paper up between the rollers 84 and 86. The paper turns somewhat down to the left, making a corner of just slightly greater than 90 degrees, partly due to the tendency to curl the paper imparted by the roller 84 which is slightly smaller than the roller 86, and partly by the weight of the paper. The paper is fed past a developing station 104 to be picked up by upper and lower rollers 106 and 108 which squeegee off any liquid developer left on the paper, and then feed the paper diagonally up to the left between upper wire guides 110 and lower wire guides 112.

The developing station 104 is constructed in accordance with the principles set forth and illustrated in Meyer L. Sugarman et al. application for U.S. Letters Pat. Ser. No. 692,234,filed Dec. 20,1967, for Compact Liquid Toner Apparatus with Straight-through Feed Path." In brief summary, and as specifically embodied in the present application, a distributor trough 114 extends traversely of the machine and is open at the top except for a screen 116 of rather fine mesh through which the liquid developer is pumped. An exposed paper 118 buckles somewhat up, as shown, partly due to riding over the liquid developer, and partly due to being buckled up by the rollers 106 and 108. The paper is developed face down, and this buckling up is quite helpful in that the exposed face does not scrape against anything that might damage it. Due to the application of the liquid toner to the lower face of the paper only, the paper is not wet to any significant degree, and what liquid there is is squeegeed from the paper by the rollers 106 and 108, and falls off into a sump 120, from which it is pumped by a conventional pump (not shown) back up through a tube (not shown) into the distributor trough 114. As will be observed, there is a flat supporting surface 122 leading from the trough 114 to the entrance to the rollers 106 and 108, and this surface has a downturned lip 124 which very nearly engages roller 108.

As the paper passes from the rollers 106 and 108, it tends to move in a substantially straight line, but engages the wire guides 110, and is deflected down against the wire guides 112. Since wire guides are used at 110 and 112, there is room for air to circulate about the paper, and this air is heated by proximity to the lamp 46, whereby the paper, which was not wet very much in the first place, is dried. The wire guides 110 and 112 are directed generally diagonally up to the left, and the bottom guide 112 has a terminal end which curves up at 126 slightly beyond the vertical to the convergence of upper and lower outfeed rollers 128 and 130 through which the paper passes for delivery face up in the delivery station 16. The delivery station includes a plate, tray, or pan 12 moving upwards to the right from the rollers 128 and 130 and terminating in an upwardly curved flange 134.

A drive motor and fan are shown at 136, and the inlet to the fan is through a generally wedge-shaped passageway 139 leading from the vacuum chamber 98. The fan is of the centrifugal type, and the outlet at 138 is into the right-hand end of the machine, thereby providing a slight positive pressure against the outer face of the paper to augment the negative pressure on the back side thereof, and also to cause air circulation up about the paper as it passes between the wire guides 110 and 112.

The motor drives a speed reducer having an output gear at 140 which preferably is connected to the speed reducer by means of an electric clutch (not shown). The gear 140 drives a chain indicated by the broken or dash line 142, and this chain passes over a cog or gear fixed on the shaft with the roller 130 to drive this roller. The roller 128 conveniently is friction driven from the roller 130, but my be positively geared thereto if desired. The chain also passes over a cog coaxial with the upper roller 86, the lower roller 84 rotating frictionally therewith, and over a gear or cog on the shaft with the lower roller 82, the upper roller 80 rotating therewith. in addition, the chain 142 passes over a cog 144 which is connected through reversing gears and an electric clutch to the roller 74 for operating the roller 74 at the proper time.

in addition to the foregoing parts, the machine is provided with an on-offswitch (not shown), and with a control unit 146 located in the lower left corner of the machine (in the position of FIG. 3). A developer storage tank 148 also is provided in the lower left portion of the machine.

When the machine is turned on by use of the on-off switch, the motor and fan 136 run. A book or other material to be copied is placed on the exposure station 14, and particularly lying on the glass plate 18 with the cover 22 overlying the material to be copied. A start button (not shown) is then pushed, and the chain 142 is started in operation through the electric clutch connecting the cog or gear 140. The roller 74 also is started in operation through the electric clutch connecting it to the gear 144, and the top sheet is fed from the stack of paper 72 through the electrostatic charging unit or station 78 and between the rollers 80 and 82 to actuate the switch 100. When the switch is actuated, the roller 74 is declutched and is no longer positively driven. However, it is free to rotate as the top sheet of paper is pulled from under it until the paper has completely passed from under the roller 74. The paper is fed up along the front reach 90 of the belt 88 until the leading edge thereof actuates the switch 102, and at this time the electric clutch driving the speed reducer output gear or cog 140 is deenergized, whereby feeding of the paper stops.

The control unit 146 is electrically interconnected with the switch 102 and the electric clutch controlling the output gear or cog 140, and as soon as the paper has stopped, the lights 44 and 46 are turned on to project the image of the page to be copied up on the charged paper carried by the front reach of the belt 90. The time of exposure is controlled by the control unit 146, as as soon as the exposure has been completed the electric clutch connected to the output cog or gear 140 is reenergized to start the chain again in operation. The paper then is fed through the rollers 84 and 86 past the developing station 104 to develop the electrostatic image on the face of the paper. The paper passes between the rollers 106 and 108, between the guides 110 and 112, and out through the rollers 128 and 130 to the delivery station 16 in faceup position, and dry to the touch. A predetermined time after the electric clutch connected to the gear or cog has been reactivated, the control unit 146 again deenergizes the clutch, and a predetermined time thereafter, if the start button is not again pushed, the entire machine shuts off. Successive copies can be made simply by pushing the start button if the copies are made within a short enough time sequence. However, if sufficient time has been allowed to elapse for the machine to shut off, the on-off switch must again be operated.

From the foregoing it will be seen that the objects of the present invention have been attained. A small electrostatic book copier has been provided that readily can rest on a table top. A book is easily supported thereon and does not slide from position, and dry copies are provided face up immediately adjacent the book or other material being copied. The travel path for the copy paper is quite short, and, in particular, the path of the exposed paper is short. Developing of the paper face down keeps the paper from being unduly wetted, and the feeding over a reentrant path allows the paper to be delivered face up. The specific embodiment of the invention as herein shown and described is for illustrative purposes. Various changes in structure will no doubt occur to those skilled in the art and will be understood as forming a part of the present invention insofar as they fall within the spirit and scope of the appended claims.

The invention is claimed as follows:

1. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, said developing station further comprising a substantially flat supporting surface leading from said distributing means towards said reentrant path, said distributing means and support surface being inclined downwardly with respect to the horizontal in the direction of travel of said paper to facilitate the flow of liquid toner from said distributing means over said support surface, and means disposed proximate the edge of said support surface remote from said distributing means for removing excess toner from said exposed surface.

2. A copying machine as set forth in claim 1, further including a sump disposed beneath said distributing means and said support surface for collecting excess liquid toner.

3. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, the means for feeding the paper along the reentrant path comprising open guides leaving the face of said paper substantially free, and further including a heat source adjacent said reentrant path and acting on said face of said paper, said copying machine further including a light source for said exposing station, and wherein said light source comprises said heat source.

4. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the 0pposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface, of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, said exposure station including, a vacuum chamber positioned opposite the surface of said paper to be exposed and a positive pressure chamber proximate said surface, and a fan assembly for withdrawing air from said vacuum chamber and exhausting same into said positive pressure chamber to create a pressure different which facilitates the maintaining of said paper in position during ex sure.

5. A photocopying machine particularly for books comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short path leading from said developing station to said delivery station, said exposing station including substantially horizontal support means for receiving one page and the corresponding side of a book, said housing further including a supporting surface extending diagonally downward from said exposing station horizontal support means for receiving the facing page and corresponding opposite side of a book, and an upwardprojecting blade supported between said exposing station horizontal support means and said diagonally downward-supporting surface and adapted to be received in the binding of a book to insure proper positioning and support of a book. 

1. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, said developing station further comprising a substantially flat supporting surface leading from said distributing means towards said reentrant path, said distributing means and support surface being inclined downwardly with respect to the horizontal in the direction of travel of said paper to facilitate the flow of liquid toner from said distributing means over said support surface, and means disposed proximate the edge of said support surface remote from said distributing means for removing excess toner from said exposed surface.
 2. A copying machine as set forth in claim 1, further including a sump disposed beneath said distributing means and said support surface for collecting excess liquid toner.
 3. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing statioN with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, the means for feeding the paper along the reentrant path comprising open guides leaving the face of said paper substantially free, and further including a heat source adjacent said reentrant path and acting on said face of said paper, said copying machine further including a light source for said exposing station, and wherein said light source comprises said heat source.
 4. A photocopying machine comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner upon which said paper rests, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short reentrant path leading from said developing station to said delivery station, said exposure station including, a vacuum chamber positioned opposite the surface of said paper to be exposed and a positive pressure chamber proximate said surface, and a fan assembly for withdrawing air from said vacuum chamber and exhausting same into said positive pressure chamber to create a pressure different which facilitates the maintaining of said paper in position during exposure.
 5. A photocopying machine particularly for books comprising a housing, an exposing station at the top of said housing and relatively toward one side thereof, a copy delivery station at the top of said housing adjacent said exposing station and relatively adjacent the opposite side of said housing, a paper storage safe in said housing, an exposure station in said housing, means for feeding paper from said safe to said exposure station, an optical system in said housing for projecting an image of material to be copied from said exposing station onto a surface of said paper at said exposure station, a developing station in said housing, means for feeding paper from said exposure station to said developing station with the exposed surface of said paper facing downwardly, said developing station including distributing means providing a layer of liquid toner, such that said toner is applied to the exposed surface only with the opposite surface of said paper remaining substantially dry, said toner being applied in substantial amounts to develop said exposed surface while precluding harmful engagement of said surface with said distributing means, and a relatively short path leading from said developing station to said delivery station, said exposing station including substantially horizontal support means for receiving one page and the corresponding side of a book, said housing further including a supporting surface extending diagonallY downward from said exposing station horizontal support means for receiving the facing page and corresponding opposite side of a book, and an upward-projecting blade supported between said exposing station horizontal support means and said diagonally downward-supporting surface and adapted to be received in the binding of a book to insure proper positioning and support of a book. 